Generally, in banking industries, a system is configured such that a host device (such as an ATM) commands a sub system (such as a card reader) to execute processing, and the sub system receives the command and executes the processing, and notifies the host device of the processing result. More specifically, magnetic cards and IC cards are used as cards for cashless [pay] or personal IDs. A magnetic card is a card in which a plastic substrate surface has a magnetic strip formed thereon, and an IC card is a card in which an IC chip is embedded in a plastic substrate; the reading and writing of information with respect to those cards are performed by a sub system (a card processing device (a card reader)) equipped with a magnetic head or IC contacts.
A card processing device is mounted onto a panel of a host device such as an ATM in normal cases. When one attempts to remove the card processing device from the panel by an illegal action, the illegal action can be detected by various methods (see Patent reference 1, for example).
In an IC card reader disclosed in the patent reference 1, when a card processing device is illegally removed from a panel and a physical attack (tampering) is carried out against a code board, tampering is detected by a tamper switch and key information inside the code board is automatically deleted.
Also, one of the requirements of a card reader with a security measure (PCI-PED standard) is that an illegal act is detected as soon as a card reader is removed from a host device. In the card reader with a PCI-PED measure, a lever to press a removal-detection switch SW is provided facing a host device mounting face (panel). By pressing the lever further into the mounting face, the SW is turned ON and the removal of the card reader from the host device is detected.    [Patent Reference 1] Unexamined Japanese Patent Application 2006-180244 (Tokkai) (Paragraph [0009])
However, in the IC card reader described in the above-mentioned patent reference 1 or the above-mentioned card reader with a PCI-PED measure, a protrusion portion for pressing a tamper switch or lever (SW/lever) needs to be provided on the card-reader-mounting face (on the back side of the panel) in the host device on the customer side. Therefore, the host device needs to be modified according to the position of the SW/lever, stroke, etc. Consequently, even if a customer wants to replace a conventional card reader with another new card reader (such as a card reader with a reinforced security function), it could not be replaced without modifying the shape and size of the mounting portion (protrusion portion, etc.).
Therefore, at least an embodiment of the present invention is devised considering the above problems, and at least an embodiment provides a tamper detection mechanism and a card processing device which, while ensuring the security function for detecting the removal of a sub system (a card processing device) from a host device, makes replacement of the sub system (card processing device) in the host device more convenient.